JPS6167051A - Dust protecting mechanism of image forming device - Google Patents

Abstract

PURPOSE:To cut off foreign matter such as toner and dust which enters a sealed space through small gap formed at a connection part between an internal cover and an internal cover or side plate by raising the atmospheric pressure in the space covered with the internal cover and side plate above the outside. CONSTITUTION:Plural common holes 23 are bored in internal covers 15-17 and an elastic member 22, but those holes are formed only in the respective covers when the elastic member 22 has sufficient air permeability. Further, holes are formed in the respective internal covers at positions facing respective support rollers. The side plate 20 is provided with a fan 24 for sucking air outside of the machine through a filter, and the side plate is provided with an air discharge hole 25. The air discharge hole 25 is made smaller than the suction hole where the fan 24 is fitted so as to raise the atmospheric pressure in the space surrounded with the internal covers 15-17 and side plates 19 and 20, and a body which provide resistance of an air flow such as the filter is fitted when necessary.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention relates to an image that reproduces and displays as a visually recognizable image image information converted into an electrical signal that is calculated or read out from, for example, an electronic computer, an image reading device, etc. In a display device or an image forming device such as a copying machine that transfers an image to a transfer material as necessary after reproduction, foreign matter such as developer or dust may be present on the inner surface of the image bearing belt or on optical components such as lenses and mirrors. This relates to a dustproof mechanism that prevents dust from adhering.

(Prior Art) Generally, an image display device or an image forming device having an endless image carrying belt as described above has a structure in which the image carrying belt is mounted on a plurality of rollers and rotated. Such an image carrying belt has toner attached to its surface and rotates within the main body of the apparatus, so that the toner on the image carrying belt is easily scattered inside the apparatus. When such scattering of toner occurs within the apparatus main body, various parts inside the apparatus are contaminated with toner, causing various problems.

For example, in an image display device that uses a transparent belt base and performs image exposure from the inside of the image bearing belt, normal image formation cannot be performed if foreign matter adheres to the inner surface of the belt.

In addition, if toner adheres to optical parts such as mirrors and lenses, it will have a fatal effect on the original functions of the device.As the toner is powder, it will penetrate deep into the complex mechanical parts and once It is not easy to clean toner that has penetrated deeply.

Particularly in devices using an image bearing belt as described above,
If toner adheres to the back side of the belt, since the back side of the belt is the surface that comes into contact with the roller, the toner will be caught between the roller and the belt, and will stick to the roller surface and belt a side, inhibiting normal image formation. , and may damage the image carrying belt. Furthermore, if the belt continues to rotate with toner adhered to the back surface of the image carrying belt, the toner will fly up in the space surrounded by the endless image carrying belt, causing the above-mentioned problems in various parts of this space. . Generally, the inner surface of the image carrying belt is a belt. The cleaning work is difficult because it is difficult to clean without removing it from the place.

In order to solve this problem, the optical components are placed in a closed space to prevent dirt, dust, toner, and other foreign matter.
There are ways to separate it from the source. However, it is practically impossible to completely seal the device, and there are cases where a sealed structure cannot be adopted due to the structure of the device, ease of assembly, cost, or other reasons.

(Object of the Invention) The present invention has been made in view of the above points, and its purpose is to prevent foreign matter such as toner from entering the inside of the image bearing belt, thereby preventing foreign matter from entering optical components such as mirrors and lenses. The objective is to provide a dust-proofing means that prevents dust from adhering.

(Summary of the Invention) The image display device according to the present invention is characterized in that, in order to achieve the above object, an endless photosensitive belt is movably wound around a plurality of rollers, and electrostatic photography is performed on the photosensitive belt. In an image display device configured to form a toner image, a closed space is formed inside the endless photosensitive belt by a partition plate and a side plate, at least one side of which is along the orbit of the endless photosensitive belt, and a closed space is formed inside the closed space. The point is that the air pressure is higher than the air pressure on the outer surface of the endless photosensitive belt.

(Example of the invention) The present invention will be explained below according to one embodiment.

Fig. W44 shows an external view of an image display device to which the present invention is applied, Fig. 2 is a partial perspective sectional view thereof, and Fig. 3 is a sectional view of the same side.

In the figure, l is the exterior cover, 2 is the transparent display glass provided on the front of the exterior cover, and 3 is the operation panel provided on the front protrusion of the cover. Do the following.

An image forming section is built inside the exterior cover 1.

This image forming section includes a drive roller 4, support rollers 5, 6, .
7 A belt-shaped photoreceptor 8 which is an image carrier stretched by these rollers, a semiconductor laser oscillator 9 provided inside this photoreceptor 8, and a scanner 1 which is a laser scanning device.
0. It is composed of an optical system for writing a latent image such as an fθ lens 11 and a mirror 12, and a developing device 13 provided outside the photoreceptor 8 in an exposure section.

A motor (not shown) is connected to the rear end shaft of the drive roller 4 to transport the belt-shaped photoreceptor 8.

Also, at least one of the support rollers 5, 6.7 (support roller 5 is preferred in the illustrated example).

It is movable in the radial direction and is configured to apply a predetermined tension to the photoreceptor 8 using a spring or the like to prevent waving, sagging, and slipping between the photoreceptor 8 and the drive roller 4. .

The belt-shaped photoreceptor 8 is made of, for example, one side of a transparent polyester sheet (in the configuration of this example, the outer side of the stretched track).
A conductive metal is deposited very thinly on the surface, and Cd is then deposited on the surface.
It is formed by applying a photosensitive material such as S.

Further, in the exposure section where a latent image is formed on the belt-shaped photoconductor 8 by the laser beam irradiated onto the photoconductor 8 through the mirror 12, a support roller 6.7 is provided so as to be in contact with the inner surface of the photoconductor 8 in the exposure section. A protective glass 14 is provided at a position slightly protruding from the common tangent line, and this protective glass 14 is raised by contact with the developing brush (brush-like spikes of developer formed by a magnet) of the developing device 13. This is to prevent vertical vibration of the photoreceptor 8 and maintain the exposure position constant to improve resolution.

In the above configuration, when a laser beam modulated by an image electric signal is emitted from the semiconductor laser oscillator 9, this laser beam is transmitted to the scanner 10. fθ lens 11. The light is irradiated onto the photoreceptor 8 in the exposure section through the mirror 12, and as the photoreceptor 8 travels and rotates, a predetermined image is developed by the developer 13.

As the photoreceptor 8 moves in the direction of arrow A, the image formed on the outer peripheral surface of the belt-shaped photoreceptor 8 is carried to a position facing the display glass, and is temporarily stopped for display. . Thereafter, the image that has been displayed is sent to the exposure section again by the movement of the photoreceptor 8, and immediately after being cleaned by a developing brush, a new image is formed through the exposure and development processes.

The image forming process in the above-mentioned image display device is disclosed in Japanese Patent Application Laid-open No. 58-98746 or Japanese Patent Application Laid-Open No. 58-58 by the applicant of the present application.
The one disclosed in Japanese Patent No.-98748 can be used, and the description thereof will be omitted here.

The dustproof device of the present invention applied to the device having the above configuration will be explained with reference to FIGS. 1 and 5.

1 is a cross-sectional side view of the vicinity of the photoreceptor 8, which is an image bearing belt, and FIG. 5 is a perspective view of the vicinity of the rollers 4 and 7. ,6.
A front inner cover 15, a lower inner cover 16, a rear inner cover 17, and a lower inner cover 18 are respectively arranged at positions facing the inner surface of the flat portion across the 7 spaces, and each cover is connected on the inside of the roller. For example, the front inner cover 15 is
As shown in FIG. 5, it covers the entire inner width of the photoreceptor 8, and its side portions are fixed to side plates 19 and 20. The other inner covers 16, 17, and 18 are also fixed across the side plates in the same manner as the front inner cover 15. Further, in the lower inner cover 18, a sleeve 21 is opened on the optical path of the laser beam in a direction perpendicular to the paper plane of FIG. 1, and the above-mentioned protective glass 14 is provided on the lower surface. Furthermore, the outer surface of each inner cover 15.16°17 is made of flexible material such as Teflon felt or sponge.
An elastic member 22 having high abrasion resistance and air permeability is bonded to a position facing the inner surface of the image carrying belt 8, and this elastic member 22 is in light contact with the inner surface of the image carrying belt 8.

On the other hand, a plurality of common holes 23 are provided in each inner cover 15, 16, 17 and the elastic member 22.

This hole may only be provided in each inner cover if the elastic member 22 has sufficient air permeability.

A hole (not shown) is also provided in each inner cover at a position facing each support roller.

Further, the side plate 20 is provided with a fan 24 for sucking air outside the machine through a filter (not shown), and the side plate 19 is provided with an exhaust hole 25. The exhaust hole 25 is smaller than the suction hole to which the fan 24 is attached in order to increase the air pressure in the space surrounded by the inner cover 15, 16, 17 and the side plates 19, 20, and if necessary, the air flow resistance such as a filter may be used. Attach something that will work.

(Effects of the Invention) As is clear from the description of the above embodiments, the dustproof means of the present invention is such that the air pressure inside the space surrounded by the inner cover and the side plate is higher than that outside. Alternatively, it is possible to completely prevent foreign substances such as toner and dust from entering the sealed space through a small gap formed at the connection between the inner cover and the side plate.

In addition, the high-pressure air in the sealed space formed by the inner cover and the side plate passes through the hole 23 or the breathable elastic member 22 and flows toward the inner surface of the belt 8 from the center to the side edge as shown in FIG. By creating the air flow 26, it is possible to completely prevent foreign matter such as toner and dust from entering the inner surface of the belt.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of the vicinity of the photoreceptor 8 of the present invention, FIG. 2 is a partial cross-sectional perspective view of the same device, FIG. 3 is a cross-sectional side view of the same device, and FIG. 5 is a perspective view of the vicinity of the roller 4.degree. 7, and FIG. 6 is a cross-sectional view of the inner cover 15. In the figure, 4.5, 6.7 --- rollers. 8-m-Photoreceptor which is an image bearing belt, 9-m-Semiconductor laser oscillator, 10--Scanner, 13-m-Developer, 14-m-
Protective glass, 15-11 front inner cover. 16--Top inner cover, 17--Rear inner cover, 18-
11 Lower inner cover, L9, 20-m-side plate. 21-m-slit, 22-m-elastic member. 23--One hole, 24--Suction fan. 25-m=exhaust hole, 26--indicates air flow.

Claims (3)

[Claims] (1) In an image display device in which an endlessly moving photosensitive belt is movably passed around a plurality of rollers and a toner image is formed by electrostatic photography on the photosensitive belt, the inner side of the endless photosensitive belt. an airtight space is formed by a partition plate and a side plate, at least one surface of which is along the orbit of the endless photosensitive belt, and the air pressure within the airtight space is higher than the air pressure at the outer surface of the endless photosensitive belt. Dust-proof mechanism for forming equipment. (2) A dustproof mechanism for an image forming apparatus according to claim 1, wherein a plurality of holes are provided on a surface of the partition plate facing the endless photosensitive belt. (3) A dustproof mechanism for an image forming apparatus according to claim 1, wherein an image exposure device is provided in the closed space.